Method of winding toroidal yokes

ABSTRACT

Projecting points on a yoke core are utilized to permit the winding of a number of separate and distinct coils as a single coil capable of subsequent separation into said separate coils. After the winding of a first coil the wire is snubbed against a first of such projecting points and the winding operation is stopped. The yoke core, however, is continuously rotated, dragging the wire across the yoke core until a second projecting point is reached, at which time the winding of a second coil is commenced.

United States Patent 1 Metzler et a1.

[ METHOD OF WINDING TOROIDAL YOKES [75] Inventors: Franklin A. Metzler; James M.

Smith, both of Emporium, Pa.

[73] Assignee: GTE Sylvania Incorporated, Seneca Falls, N.Y.

[22] Filed: May 1, 1972 [21] Appl, No.: 248,825

[52] 0.8. CI. 29/605, 242/4 R, 242/7.03, 335/213 [51] Int. Cl. 1101f 7/06 [58] Field of Search 29/6 05; 242/4, 4 R, 242/4 B, 4 BE, 7.03; 335/210, 213

[56] References Cited UNITED STATES PATENTS 3,008,108 11/1961 Baker et a1 29/605 UX 2,437,513 3/1948 Gethmann 335/213 3,559,899 2/1971 Fah rbach 242/4 B 1 Oct. 23, 1973 3,652,966 3/1972 Meier 335/213 X 3,426,425 2/1969 Brown et al. 3,196,523 7/1965 Bell 29/605 Primary Examiner-Richard J. l-lerbst Assistant Examiner-Carl E. Hall Attorney-Norman J. OMalley et al.

[57] ABSTRACT Projecting points on a yoke core are utilized to permit the winding of a number of separate and distinct coils as a single coil capable of subsequent separation into said separate coils. After the winding of a first coil the wire is snubbed against a first of such projecting points and the winding operation is stopped. The yoke core, however, is continuously rotated, dragging the wire across the yoke core until a second projecting point is reached, at which time the winding of a second coil is commenced.

3 Claims, 8 Drawing Figures PAIENIEnncr 23 Ian 3 766 641 I SHEET 1 or '2 PATENTED 0812 3 I975 SHEET 2 0F 2 v METHOD OF WINDING TOROIDAL YOKES BACKGROUND OF THE INVENTION This invention relates to deflection yokes for cathode ray tubes and more particularly to a new and novel method of winding such yokes. The method is of particular advantage in the winding of toroidal yokes.

It is known to make toroidal deflection yokes for cathode ray tubes such yokes comprise a hollow, magnetically permeable core having a plurality of coils of wire wound longitudinally thereabout. That is, each of the turns is substantially parallel to the longitudinal axis of the core. These yokes generally have four distinct and separate coils, two for the horizontal deflection and two for the vertical deflection; however, winding patterns having ten or more coils have been made. Such yokes have been semi-automatically wound on a yoke winding machine which basically has a winding head including a closed circular track containing a wire loaded bobbin, the yoke being positioned with the circular track substantially in the center of the core. In operation, the bobbin revolves around the circular track in a vertical plane while the yoke core is rotated in a horizontal plane according toa specific wiring or winding pattern. In all prior art devices of this type it was necessary, after the winding of a first one of the coils, for the operator to stop the machine, sever the-wire, fix the cut end so that it would not be lost (generally by taping it to the core), index the core to the proper position for the next winding, and restart the machine. As noted above, the procedure had to be repeated for each of the coils and resulted in a time-consuming operation which greatly increased the cost of the yoke.

OBJECTS AND SUMMARY OF THE INVENTION It is, therefore, an object of this invention to obviate the disadvantages of the prior art.

It is another object of the invention to enhance the method of winding toroid yokes.

It is yet another object of the invention to reduce the cost of winding toroid yokes.

Still another object of the invention is to increase the speed with which such yokes can be wound. I

These objects are accomplished in one aspect of the invention by the provision of a method of winding the necessary plurality of coils for a yoke as a single coil and subsequently separating this single coil into the desired plurality.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1-6 are sequential perspective views of the steps of the invention;

FIG. 7 is a perspective view of a yoke immediately after winding; and

FIG. 8 is a perspective view ofa yoke after a slew has been separated to form at least two distinct coils.

DESCRIPTION OF THE PREFERRED EMBODIMENTS For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in conjunction with the above-described drawings.

Referring now to the drawings with greater particularity, in FIG. 1 there is shown a yoke core 10 in a position to be wound with wire 12. The yoke core 10 comprises a frusto-conical, hollow body 14 which can be a magnetic ferrite material which can be covered with a plastic housing. The body 14 has a top 16, a bottom 18 and an angled wall 20. This angled wall 20 is provided with at least two slew points 22 which are displaced from one another in predetermined locations. The slew points are preferably constructed from a non-magnetic material, and can be attached to wall 20 by any suitable method; e.g., if the slew points are attached directly to the ferrite material they can be glued there-upon; if the plastic housing is utilized they can be glued thereto or be molded in as an integral element. The configuration of the slew points shown is substantially triangular; however, other configurations such as cylindrical can be employed.

Yoke core 10 in FIG. 1 is shown operationally with a portion of a closed track 24 in position. For further details of this portion of the winding mechanism, reference can be had to US. Pat. No. 3,559,899. At the start of the winding cycle an end 26 of wire 12 is temporarily affixed to wall 20, as by tape 28. The winding of what will become a first coil is commenced by rotating the yoke core 10 in a horizontal plane while rotating the closed track 24, with its wire containing bobbin, in a vertical plane thus laying turns of wire 12 about the core. The winding continues for a desired number of turns at the termination of which the wire 12 coming from track 24 will be in contact with a first slew point 22a, which in this instance is located near the bottom 18 of core 10. When this point is reached the winding of the wire stops and a slewing tool 30 is indexed into a position to engage the wire 12, as shown in FIG. 2; however, the rotational movement of core 10 continues. This rotating action of the core 10 catches the wire 12 against the first slew point 22a and the slewing tool 30 causing the wire 12 to be dragged across the angled wall 20 substantially transversely to the normal winding direction, thus forming a slew 32 (the term slew refers to the dragged portion'of the wire). The slewing continues for a predetermined distance until a second slew point 22b is in position beneath the track 24 (See FIG. 4). At this position the winding of what will become a second coil is commenced by starting the winding operation. This action automatically removes wire 12 from slewing tool 30, which is then withdrawn from its operative position, and the winding of the second coil takes place (see FIG. 6).

In FIG. 7 is shown a completed coil. Herein, it will be seen that, if necessary, further coils can be wound by laying turns of wire over a previously formed slew 32. Likewise, a slew can be formed over previously wound turns. The termination 34 of the winding of the last coil is temporarily affixed to the core 10, as by tape 36. This completes the winding of the coil. It is to be noted that in the interest of simplicity and clarity only two slew points have been shown; however, this is not meant to be restrictive. Far more than two slew points can be employed and many coils can be wound as a single coil capable of later separation.

When the final wiring of the yoke is attempted all slews 32 are cut (see FIG. 8) thus forming the desired number of separate coils and the ends of these separate coils are connected to their appropriate circuitry; usually these connections are made to a printed circuit board attached to one end of the yoke.

It will be seen from the above description that there is herein provided a new and novel method of fabricating toroidal yokes. It is simple and inexpensive and greatly facilitates the winding of such yokes while obviating the disadvantages of the prior art.

While there have been shown and described what are at present considered to be the preferred embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims.

What is claimed is:

1. A method of winding coils upon a toroidal core, said core comprising a substantially frusto-conical hollow body having a longitudinal axis, the outer surface of said body containing thereon at least two spaced apart slewing points which project therefrom, said method comprising the steps of: positioning said body in a manner to be wound; fixing a first end of a supply of wire to said body; rotating said core about said longitudinal axis and simultaneously commencing the winding of said wire substantially parallel to said longitudinal axis, said winding continuing until a first of said slewing points is engaged by said wire; stopping said winding; engaging said wire with a slewing tool; continuing said rotation of said core, whereby said wire is slewed about said core to a second of said slewing points which said wire engages; and commencing again the winding of said wire.

2. The method of claim 1 wherein said core is the core for a toroidal yoke for a cathode ray tube.

3. The method of claim 2 wherein said core is subsequently removed from said winding position and said slewed wire is cut between said slewing points to form two separate coils. 

1. A method of winding coils upon a toroidal core, said core comprising a substantially frusto-conical hollow body having a longitudinal axis, the outer surface of said body containing thereon at least two spaced apart slewing points which project therefrom, said method comprising the steps of: positioning said body in a manner to be wound; fixing a first end of a supply of wire to said body; rotating said core about said longitudinal axis and simultaneously commencing the winding of said wire substantially parallel to said longitudinal axis, said winding continuing until a first of said slewing points is engaged by said wire; stopping said winding; engaging said wire with a slewing tool; continuing said rotation of said core, whereby said wire is slewed about said core to a second of said slewing points which said wire engages; and commencing again the winding of said wire.
 2. The method of claim 1 wherein said core is the core for a toroidal yoke for a cathode ray tube.
 3. The method of claim 2 wherein said core is subsequently removed from said winding position and said slewed wire is cut between said slewing points to form two separate coils. 